반면교사로

In a sentence

• 그의 실패를 반면교사로 삼아 나는 더 열심히 노력했다.

  Taking his failure as a lesson, I worked harder.

  The word '반면교사로' here means 'as a lesson by example of failure or a negative outcome,' referring to learning from someone's mistakes.

• 반면교사로 배우는 것이 중요하다는 것을 항상 잊지 말아요.

  Always remember that learning from examples of failures is important.

  In this context, '반면교사로' emphasizes the importance of such learning experiences.

• 그 사건은 많은 사람들에게 반면교사로 남았다.

  That incident remained as a cautionary lesson to many people.

  Here, '반면교사로' implies that the incident serves as a source of guidance or a warning through its nature or results.